Using solar with a battery back-up is a costly alternative to a gas powered generator.
- Each battery costs in the neighborhood of $450-$500.
- Depending on the load of the critical circuits, your home could require 20 to even 40 batteries.
Also this may only give you up to 16-18 hours of backup power.
Keep in mind too that batteries are also not permanent and have to be replaced. The average life expectancy is only 5 years if maintained properly.
If you have the capabilities, installing a natural gas generator is a better option to a gasoline powered generator.